What Makes Drivers Not Liable For Murder?

If you get drunk, grab a loaded gun, go into a public space and shoot one or more people, what charge will be laid?  Murder, right, 25-to-life.  If you get drunk, pick up a wrench and smash it over someone’s head, what charge will be laid?  Murder, of course, 25-to-life.  If you get drunk, get into your car and mow down pedestrians on the street, what charge will be laid?  Vehicular manslaughter if we are lucky, 4 or 5 years.

What’s wrong with this picture?  Why do killers with cars get away with murder?